1. Field of Invention
The present invention relates to conveyor roller systems and, more particularly, to a conveyor roller designed to permit rotation in only one direction.
Various breaking mechanisms for controlling the rotational movement of conveyor rollers are well known to those skilled in the art. In the materials handling industry it is desirable to control the rotational movement of a conveyor roller in order to limit the movement of articles and packages being carried thereon to one direction.
For example, U.S. Pat. No. 3,918,561 discloses a brake roller for conveyor systems wherein a tube rotates about a stationary shaft and a speed multiplying transmission within the tube powered by the rotation of the tube operates centrifugally operated friction brake members to prevent an excessive rate of tube rotation. Similarly, U.S. Pat. No. 5,147,020 discloses a conveyor roller brake that is carried within the confines of a conveyor roller.
However, such conveyor brake mechanisms are mechanically complex requiring numerous component parts and a high cost of manufacture. Thus, the Unidirectional Conveyor Roller of the present invention has been developed to provide a cost effective mechanism for controlling rotation of the conveyor roller to a single direction.
2. Description of Related Prior Art
U.S. Pat. No. 3,918,561 to Sven E. Isacsson discloses a brake roller for conveyor systems wherein a tube rotates about a stationary shaft and a speed multiplying transmission within the tube powered by the rotation of the tube operates centrifugally operated friction brake members to prevent an excess rate of tube rotation. Positive drive means are interposed between the tube and the transmission and the friction brake members centrifugally operated are constructed as to make the most efficient use of the centrifugal forces available.
U.S. Pat. No. 5,147,020 to Dale Scherman et al. discloses a conveyor roller brake that is preferably carried within confines of a conveyor roller and includes a friction surface carried by the conveyor roller and a brake shoe that is maintained continuously in biased engagement with the friction surface and is selectively engagable or disengagable with respect to a non-rotatable hub element thereby selectively permitting the brake shoe to rotate freely with the conveyor roller in frictional engagement with the friction surface or to be arrested in its rotation so that relative rotation of the roller with respect thereto provides continuous roller braking through frictional sliding of the brake shoe in biased engagement with the friction surface.
U.S. Pat. No. 3,899,063 to Orray R. Pollard discloses a roller mechanism associated with roller conveyor systems for controlling buildup of momentum of such systems during use. In this system, a hammer is mounted within one or more substantially cylindrical rollers on the axes thereof. Anvils are positioned on the roller to rotate therewith and to engage the hammer. The hammer is capable of pivotally disengaging the anvils to allow resisted rotational motion of the rollers.
U.S. Pat. No. 3,576,242 to Harold H. Mumma discloses a gravity roller conveyor including special braking rollers at spaced intervals which have stationary brake drum attachments adjacent to one of their ends. A pair of brake shoes located within each of the brake drums is pivotally mounted to and rotatable with each braking roller. As the speed of the conveyor rollers increases under a moving load, the centrifugal force acting upon the brake shoes propels them outwardly against the urging of their springs and into engagement with the braking surface of the drum in order to retard speed.
U.S. Pat. No. 4,266,659 to Louis H. Meyer et al. discloses an accumulating roller conveyor for conveying articles having a frame and a plurality of conveyor rollers each conveyor roller including a cylindrical drive sleeve supported by longitudinal shaft extending therethrough and rotatably supporting the drive sleeve thereon. This roller conveyor features a one-way clutch mechanism being engagable between each conveyor roller shaft and the associated conveyor roller sleeve to cause the shaft and the sleeve to rotate as a unit to hold out of contact with the drive belt the conveyor rollers in contact with a stopped article as long as the contact article is stopped.
U.S. Pat. No. 3,209,880 to Gilbert Dietiker discloses a cargo handling apparatus with an automatic braking mechanism for slowing down and/or stopping runaway cargo. An automatic speed control cargo roller is provided for use in a floor recess. The roller has a belt operated mechanism capable of stopping rotation of the roller when a predetermined speed is achieved. The stopped roller activates a brake shoe member to engage itself with the load thereby preventing the load from further movement.
U.S. Pat. No. 3,312,320 to Nicholas J. Froilo discloses a conveyor braking roller including a speed retarding roller for advancing packages and pallets automatically from a loading position to an unloading position without application of propelling power. This device utilizes a complex gearing system and does not limit rotation to only one direction.
Finally, U.S. Pat. No. 1,821,618 to Joseph P.Crowley discloses an apparatus for the manufacture of sheet glass which features an overrunning clutch. In the event that the linear speed of a glass sheet exceeds the peripheral speed of the conveyor rollers, the sheet is allowed to drive the rollers faster than they are positively driven along the conveyor. When this occurs, the overrunning clutch is actuated and the glass sheet rides freely over the conveyor rollers.
The present unidirectional conveyor roller or One Way Roller, as it has become known in the industry, consists of a cylindrical metal tube having conventional ball bearing assemblies installed at either end thereof. An elongated shaft extends through the pair of ball bearing assemblies and through the hollow tube projecting a short distance at either end thereby permitting rotation of the tube about the shaft in the manner of a conventional conveyor roller.
The One Way Roller of the present invention also includes a roller clutch bearing which is installed on the shaft and carried on the interior of the hollow tube to limit rotation to one direction only.
In the present One Way Roller the shaft is retractable into the roller body at one end to permit convenient installation into the supporting frame of the conveyor system.
In view of the above, it is an object of the present invention to provide a conveyor roller, which permits rotation in only one direction to control the movement of articles being conveyed thereon.
Another object of the present invention is to provide a unidirectional conveyor roller which can be conveniently installed in a pre-existing conveyor system to limit the movement of packages conveyed thereon to one direction.
Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention.